Stop gage for band saw conveyor or the like

ABSTRACT

A dead stop for positioning stock on the conveyor of a band saw to establish a desired cut off length. The stop member is mounted on a carriage which rides along a rail adjacent the conveyor on the downstream side and which may be clamped to the rail at a desired point. The stop member is hinged for upward swinging movement with provision for relative retreating movement along the hinge axis. A cam and cam follower are interposed between the stop member and the carriage with a fluid actuator for retracting and swinging up the stop member to permit a severed work piece to be transported along the conveyor for discharge. Upon impact the stop member retreats against the force applied by the actuator followed by prompt restoration to a reference position. The movement of the carriage and the clamping to the rail as well as the swinging of the stop member are all controlled from a control station at the band saw where the position of the stop member is accurately and continuously indicated on a calibrated tape which is subject to continuous tensioning and take-up by a negator spring.

United States Patent 91 Wilkin [451 Feb. 27, 1973 STOP GAGE FOR BAND SAWCONVEYOR OR THE LIKE John P. Wilkin, Schaumburg, Ill.

[73] Assignee: Armstrong-Blum Manufacturing Company, Chicago, Ill.

22 Filed: June 29, 1970 21 Appl.No.:50,532

[75] Inventor:

[52] US. Cl. ..83/20l, 83/268, 83/419, 83/467 A, 83/468 [51] Int. Cl...B26d 7/16 [58] Field of Search....83/419, 468, 467 A, 467, 201,83/268, 269, 522, 201.07; 269/320, 317, 318

3,474,693 10/1969 Wilkie et a1. 83/201.07 3,141,367 7/1964 Keener et a].83/268 X 3,155,242 11/1964 Magloire ....83/269 X 3,304,824 2/1967 Hess,Sr. et a1. ..83/269 X Primary Examiner-James M. Meister Attorney-Wolfe,Hubbard, Leydig, Voit and Osann [5 7 ABSTRACT A dead stop forpositioning stock on the conveyor of a band saw to establish a desiredcut off length. The stop member is mounted on a carriage which ridesalong a rail adjacent the conveyor on the downstream side and which maybe clamped to the rail at a desired point. The stop member is hinged forupward swinging movement with provision for relative retreating movementalong the hinge axis. A cam and cam follower are interposed between thestop member and the carriage with a fluid actuator for retracting andswinging up the stop member to permit a severed work piece to betransported along the conveyor for discharge. Upon impact the stopmember retreats against the force applied by the actuator followed byprompt restoration to a reference position. The movement of the carriageand the clamping to the rail as well as the swinging of the stop memberare all controlled from a control station at the band saw where theposition of the stop member is accurately and continuously indicated ona calibrated tape which is subject to continuous tensioning and take-upby a negator spring.

8 Claims, 20 Drawing Figures PATENIEBFEBZYIBYES 3,718,051

sum 1 BF 9 PATENTEDFEBZYIHYS SHEET 3 OF 9 n .f! H a PATENTED FEB 2 7I973 SHEET 0F 9 Wm M? K 3 STOP GAGE FOR BAND SAW CONVEYOR OR THE LIKE Itis an object of the present invention to provide a dead stop which ispositive and precise, which enables accurate cut-off of a series ofworkpieces of the same or different length from a length of stock, andin which all functions are conveniently controllable from a controlstation at the band saw. It is a more specific object to provide a deadstop which is remotely positionable, which is securely clamped inlocking position and which permits prompt swinging into an out of theway position for continued movement of the severed workpiece along theconveyor, all by means of fingertip manipulation of the controls andwith constant and ac curate indication of the cut-off length for whichthe device has been set.

It is another object of the present invention to provide a dead stopwhich is capable of intercepting and positioning heavy stock, which hasprovision for momentary retreating movement to absorb the energy ofimpact followed by immediate restoration to reference position, andwhich has a novel design of cam and actuator interposed between thecarriage and the stop member to bring about sequential retraction andswinging movement for prompt freeing of the severed work piece andprompt lowering thereafter into blocking position to minimize the timelost between successive cuts.

In one of the aspects of the invention it is an object to provideconstant and positive indication, at the control station, of the cut-offlength for which the stop is set with continuous tensioning take upregardless of whether the carriage is mounted on the near" or far sideof the conveyor.

Other objects and advantages of the invention will become apparent uponreading the attached detailed description and upon reference to thedrawings:

FIG. 1 is a view in elevation of a band saw and conveyor assemblyincorporating a dead stop constructed in accordance with the presentinvention.

FIG. 2 is a plan view corresponding to FIG. 1.

FIG. 3 is a perspective view of the dead stop carriage and stop member.

FIG. 4 is a fragmentary vertical section taken along the line 4-4 inFIG. 3.

FIG. 5 is a fragmentary horizontal section looking along the line 55 inFIG. 4.

FIG. 6 is a fragmentary vertical section taken along the line 66 in FIG.3 and offset from the section 4--4.

FIG. 7 is a horizontal section taken along the line 7- 7 in FIG.6.

FIG. 7a is a fragmentary section taken along the line 7a-7a in FIG. 7.

FIG. 8 is a fragmentary section taken along the line 8-8 in FIG. 6.

FIG. 9 is a fragmentary horizontal section taken through the actuatoralong line 99 in FIG. 3.

FIGS. 10 and 11 are fragmentary cross sections taken along the linesl010 and 11-11 respectively in FIG. 9

FIG. 12 is an enlarged side elevation of the tape cartridge and take upmeans looking along the line 1212 in FIG. 2 and with the housingpartially broken away.

FIG. 13 is a broken vertical section taken along the line 13-13 in FIG.12.

FIG. 14 is a top view looking along the line 14-14 in FIG. 12.

FIG. 15 is fragmentary elevation showing the connection of thecalibrated tape to the carriage.

FIG. 16 is a fragmentary section looking along the line 16-l6 in FIG.15.

FIG. 17 is a simplified control diagram showing the control valves atthe control station and with the connecting lines indicatedschematically.

FIG. 18 is a fragmentary perspective showing the run of tape to thecontrol station employed when the carriage is on the opposite side ofthe conveyor.

FIG. 19 is a schematic diagram showing means for automatic positioningof the carriage.

While the invention has been described in connection with a preferredembodiment, it will be understood that I do not intend to be limited tothe particular embodiment shown but intend, on the contrary, to coverthe various alternative and equivalent constructions included in thespirit and scope of the appended claims.

Turning now to the drawings, a typical production installation is shownin FIGS. 1 and 2 including a band saw 20 having a fixed table 21 and aforwardly and backwardly reciprocating frame 22 carrying a saw blade 23,the blade being oriented in the direction of movement of the frame. Themeans for driving the saw and reciprocating the frame on which it ismounted do not per se form a part of the present invention, and it willsuffice to say that such functions are controlled in the conventionalway from a control panel 24 at the front of the machine.

Leading into the saw table from the left hand side is an inlet conveyor25 carrying a lengthy piece of stock 26 which is to be cut intopredetermined shorter length. The stock passes between the jaws of avise 27 mounted on the table 21. At the right hand, or downstream, sideof the saw is a conveyor 30 having longitudinal frame elements 31,32 andsupporting structure 33. Spaced along the top surface of the conveyorare conveying rollers journaled in supports 36. Conventional means areprovided for driving all of the conveyor rollers at the same speed fortransport of the stock into position to make a cut and for thereaftertransporting the severed workpiece along the conveyor to an ejec'tingstation.

In accordance with the present invention a dead stop is provided on theconveyor at the downstream side of the saw consisting of a stop memberwhich extends transversely of the conveyor in the path of movement ofthe stock and a supporting carriage which is mounted on a longitudinallyextending rail, with means for positively clamping the carriage to therail for precise positioning of the stop member. Further in accordancewith the invention, the stop member mounted for upward swinging movementabout a hinge axis with provision for a limited amount of axial movementand with a combined actuator and cam assembly for sequential axialretraction and upward swinging out of the path of the severed workpiecefor continued movement of the latter along the conveyor to the point ofdischarge.

Thus, referring to FIGS. 1-6, a rail 40 extends along the side of theconveyor, the rail being in the form of a relatively massive strip ofmetal having upper and lower parallel edges 41,42 and front and rearfaces 43, 44. The rear face 44 is firmly secured to the side frame 32 ofthe conveyor on stand-offs 45, 46. Riding on the rail 40 is a carriagewhich is centrally recessed to provide upper and lower arms 51, 52 whichembrace the upper and lower edges of the rail and a wall 53 in Cconfiguration (FIG. 4) defining a central space 54 in which the rail isreceived. The carriage is reinforced by integral end members 55, 56,arranged vertically and parallel to one another and by intervening ribmembers.

57, 58. The bottom of the carriage is enclosed by a bottom plate 59.

For the purpose of driving the carriage along the rail, the carriageincludes a selficontained hydraulic motor 60 having a pinion 61 and anidler gear 62 (see FIGS. 4 and the idler gear meshing with a rack 63which is secured to the front face 43 of the rail. The hydraulic motoris of conventional design having supply orifices 65, 66 which arealternatively pressurized to drive the motor in one direction or theother. As discussed in a later paragraph, the motor and the othercontrollable elements in the carriage are remotely operated from acontrol station located at the band saw.

Anti-friction means are provided for supporting the carriage on the railas it is moved along. Such anti-friction means includes load rollers 70(see FIGS. 7 and 7a) which engage the top edge of the rail, a first setof lateral rollers '71, 72 which engage the side faces of the railadjacent to the upper edge and a second set of rollers 73, 74 whichengage the side faces along the bottom edge. Such suspension provides alimited amount of clearance 75, during transport, along the bottom edgeof the rail adjacent a fixed shoe 76.

For clamping the carriage to the rail, a shiftable shoe is providedwhich is loosely received in the upper arm 51 and which has means forcrowding it downwardly against the rail for relatively upward liftingmovement of the carriage to take up the clearance space 75 at the loweredge of the rail so that the rail is powerfully clamped top and bottom.Thus, referring to FIGS. 6 and 8, a shoe 80 loosely fitted in an opening81 in the top arm is acted upon by a cam 82. The cam is mounted forrotation about a shaft 83 which extends between the internal ribs 57 58of the carriage. For rocking the cam about the shaft in oppositedirections with a high mechanical advantage, the cam is provided with apair of arms 84 which are connected to a reversible fluid actuator 85 bymeans of a pin connection 86. The actuator has fluid connections 87, 88which may be alternatively pressurized by remote control. When theconnection 87 is pressurized, extension of the actuator causes clockwiserotation of the cam 82 which crowds downwardly against the shoe 80. Forthe purpose of accommodating the slight rocking movement which occursincident to the swing of the arms 84, the actuator is mounted on aswivel 89. Pressurizing the connection 88 contracts the actuator torelieve the force against the shoe 80, permitting the carriage to settleand reestablishing clearance at the bottom edge of the rail for freemovement of the carriage to a new position.

In accordance with the present invention, a stop member in the form ofan arm is provided, hinged to the carriage, and having a presented stopsurface which extends the width of the conveyor, the hinge not onlypermitting upward swinging movement but also movement endwise of thehinge axis. Referring to FIG. 3 the stop member, generally indicated at100 has spaced arms 101, 102, secured by welding or equivalent to a stopplate 103 having a stop surface 104 along the presented edge. Areinforcing plate 105 bridges the arms 101, 102 to provide a rigidbox-like construction. The arms are secured to the ends of a shaft 110,extending parallel to the rail, by rigid bolted connections 111, 112respectively. The shaft is mounted for swinging movement, and axialmovement, in a sleeve 115 having a base 116 which is secured to padsprovided at the top of the carriage side members 55, 56.

In carrying out the present invention, the sleeve 115 includes anintegral reversible pressure actuator for imparting endwise movement tothe shaft as well as internal cam track which engages a cam follower onthe shaft, the cam track having an initial, axially extending portion,so that the stop member is first retracted away from the severedworkpiece, and an angled or helical portion for rocking the shaft sothat the stop member is swung upwardly out of the way of the workpiecefor continued movement of the workpiece to the point of discharge fromthe conveyor. Thus referring to FIG. 9, the sleeve which mounts theshaft has combined sealing and bearing assemblies 121, 122 at the endsand is centrally recessed to form an annular chamber 123. Secured to theshaft 110, and movable within the chamber 123 is a piston 125. Tofacilitate mounting of the piston on the shaft, the shaft may be formedin two pieces joined by a threaded, pinned connection 126. Providingcommunication with the opposite ends of the annular chamber 123 arefluid pressure connections 127, 128. It will be apparent thatpressurizing the connection 127 will cause the piston and the shaft 110to move in the retracting" direction, that is, to the right as viewed inFIG. 9.

The cam track and cam follower, which are effectively interposed betweenthe stop member and the carriage, are incorporated in the iefthandportion of the supporting sleeve US. As shown in FIG. 9 the sleeveincludes an annular insert 130 which is milled out to form a cam trackmade up of an initial axially extending section 131 and an angled, orhelical, section 132. Snugly fitted into this cam track is a camfollower in the form of a roller 133, which is slightly recessed into acavity 134 formed in the shaft, and which is secured to the shaft by amounting screw 135. For providing a smooth and snug fit between theshaft and the annular insert 130, a sleeve 136 made of bronze orsuitable anti friction bearing material may be interposed between thetwo.

In order to establish a reference position for the shaft 110, and hencefor the stop surface 104 which engages the stock, an axially positionedreference stop is provided within the assembly. This reference stop,indicated at 140 in FIG. 9, is the surface at the end of the insert 130against which the piston 125 seats when the piston is urged fully in thedirection of the oncoming stock by fluid pressure applied to the inlet128. Thus under normal conditions, with the stop surface 104 in positionto receive the oncoming stock, the parts are as shown in FIG. 9.

It is one of the features of the present invention that when theoncoming end of a length of stock strikes the stop surface 104, the stopmember 100, and the shaft 110, are free to yield to take up the impact,with absorption of the kinetic energy in the stock. Such yielding, withsubsequent restoration to reference position, is facilitated by use ofan accumulator 141 of known design connected to the orifice 128. Whenimpact occurs the cam follower 133 on the shaft retreats in the straightsection 131 of the cam track accompanied by movement of the piston 125into the space 123 displacing the oil or other fluid into theaccumulator 141. The energy is dissipated in the sudden and turbulentflow of the fluid and by a momentary increase of pressure in theaccumulator. Immediately after the impact the pressure in theaccumulator and that of the pump re-asserts itself to cause movement ofthe piston to the left until bottoming takes place at the reference stop140, thereby positioning the stock which is in engagement with thesurface 104 in a precise position for cut-off.

As the forward cutting stroke of the band saw frame is completed, thepressure applied to the piston 125 is reversed, that is, pressure fluidis applied to the conduit 127 by a suitable valve, conduit 128 beingconnected to a sump. This causes the shaft to move straight back,retracting the stop surface 104 from the engaged end of the work pieceas the cam follower 133 traverses the initial straight portion of thetrack, followed by upward swinging movement of the stop member 100 asthe cam follower engages the helical portion 132 of the track, until thepiston bottoms at the opposite end of the stroke, with the stop membercompletely clear of the work piece. The conveyor is then operated toconvey the severed workpiece as quickly as possible to a point beyondthe dead stop for lateral discharge, for example, by an ejector barwhich sweeps broadwise across the conveyor as covered in my copendingapplication Ser. No. 50,706, filed June 29, 1970 now US. Pat. No.3,655,025 issued Apr. 11, 1972. After this the pressure applied to theconduits is again reversed, promptly lowering the stop member 100 intothe path of movement of the oncoming stock in readiness for the nextcut-off cycle. Because the cam follower 133 on the shaft is confinedwithin the cam track, the lowering of the stop member occurs, althoughpromptly, in a positive and controlled fashion until the piston seats onthe reference surface 140.

In accordance with one of the aspects of the invention, a calibratedtape connected to the carriage leads to the control station at thebandsaw for direct indication of the distance between the stop surface104 and the saw blade, with means for maintaining the tape underconstant tensioned take-up. Thus, referring to FIGS. 12-16, the tape,indicated at 150, is anchored to the carriage by a bracket 151 (FIG. andis supported in a shallow longitudinally extending trough 152 (FIG. 6)formed in a thin metal bridge or apron 153 which spans the space betweenthe rail 40 and the adjacent frame member 32 of the conveyor. The tapeis guided from its anchoring bracket 151 into the trough at its remote,or moving, end by a curved spoon 154 which is integral with the bracket.

At the control station the tape 150 passes into a housing 155 (FIG. 12)which contains an idler 156 mounted on a shaft 157. Arranged above thetape is an index 158 which permits direct reading of the tapecalibrations. From the idler 156 the tape passes into a reservoirhousing 160 having a reservoir or take-up reel 161 mounted on a shaft162 and having a hub 163. Wound about the hub is a negator spring 165.The spring is secured to the hub at 166, and the other end of the springis wound about a negator spring reel 167 rotatable about a centralbearing pin 168. The negator spring is prestressed so that it tends,when left to its own devices, to wind itself tightly about the reel 167and to unwind from the hub. This tendency of the negator spring tounwind from the hub causes a small amount of relatively constant torqueto be applied to the reel 161 to maintain the tape under a constantcondition of tensioned take-up. When the carriage moves outwardly alongthe conveyor, the paying out of the tape is accompanied by reversewinding of the negator spring storing energy therein. When the carriagemoves in the opposite or return direction, the energy stored in thespring applies clockwise winding torque to the reel 161, and the tape isdrawn back into its reservoir.

It is one of the features of the invention that such take-up anddisplay, at the control station, may be used even where the carriage ismounted on a rail which is at the back side of the conveyor. Referringto FIG. 18 the carriage, indicated at 50a, and which carries a stopmember 1000, rides on a rail 40a. The tape 150a, which is connected tothe carriage in the vertically edgewise position, passes about a flangedidler wheel 156a at the back side of the conveyor and is directedforwardly, with a 90 twist, into the housing a corresponding to thehousing 160 shown in FIG. 12. An index 158a secured to the housingprovides for direct reading of the tape at the control position.

All of the controls for the functions of the dead stop described aboveare, in accordance with the invention, available to the operator withoutleaving the control station at the front of the band saw. As shown inFIG. 17 (see also FIG. 1) a small control panel 170 is provided havingcontrol valves connected ,to a pressure line 171 and a sump line 172. Inthe simplest aspect of the invention, conventional four-way valves maybe employed for applying pressure to the associated actuators, eitherdirectly or in the reverse sense. Thus in a simplified system a four-wayvalve 173 is provided connected to lines 65, 66 and having forward andreverse" settings for causing the motor 60 to drive the carriage in theforward and reverse directions. Similarly a four-way valve 174 is used,connected to the clamping actuator as via lines 87,88, and movablebetween clamping and unclamping positions, to control the clamping ofthe carriage with respect to the rail upon which it is mounted. Finally,a valve 175 having up" and down positions is connected to lines 127, 128leading to the actuator sleeve 115 for raising and lowering the stopmember 100. In a practical case it would be understood that thesimplified fluid circuitry shown in FIG. 17 may be replaced by moresophisticated control elements utilizing, if desired,electrically'controlled pilot valves having control switches at thecontrol station for accomplishing the respective functions.

To complete a practical setup, the fluid actuated vise, indicated at 27in FIG. 1, and controlled from the control console 24, is opened whenstock is advanced and closed after the leading end of the length ofstock is seated upon, and positioned by, the stop surface 104 inreadiness for making the out.

Any desired means may be used for supporting and guiding the controllines 65, 66, 87, 88 and 127, 128 connected to the movable carriage. Onesuch means is a progressively foldable carrier 176, having a terminal177, shown in FIG. 1 and which will be recognized by those skilled inthis art. Stationary lines are run from the terminal to the controlpanel.

While the operating sequence and the inherent ad vantages of thedisclosed dead stop assembly will be apparent from the foregoingdiscussion, it may be helpful to review a typical operating sequence. Itmay be assumed, for example, that it is desired to cut a length of stockslightly in excess of 20 feet into four 5-foot sections. With thecarriage freed, the valve 173 is operated to drive the carriage to apoint along the rail where a displacement of exactly 5 feet is indicatedat the index 158 for the tape 150. The valve 174 is thrown to theclamping position, pressurizing the line 87 to rock the arm 84 upwardlyso that the cam 82 crowds the shoe 81 against the upper edge of therail, causing the rail to be clamped tightly between the upper and lowerarms 51, 52 in the carriage. Although only a single upper shoe 81 isused for clamping purposes, it is found, particularly in view of theimpact absorbing characteristics of the assembly, that this is adequateto lock the carriage against any displacement in use.

The conveyor is energized to convey the stock 26 toward the stop member,and when the leading end engages the stop surface 104 the stop membermomentarily retreats, with flow of fluid into the accumulator 141, butas soon as the impact has occurred the pressure of the fluid again seatsthe piston at the reference surface 140 (FIG. 9) for precise positioningof the leading end of the stock. The vise 27 is then closed tight andthe saw blade 23 is advanced, cutting off a 5-foot length of stock toform the workpiece. The valve 175 is then thrown to the up position.This causes endwise retraction of the stop surface 104 away from theengaged end of the work piece and upward lifting of the stop member 100to an out-of-the-way position. Operation of the conveyor rollers thencauses the work piece to be run forwardly to a position of ejection orunloading, following which the valve 175 is restored to its downsetting, thereby lowering the stop member 100 into its obstructingposition in readiness for anew cutoff cycle.

While the motor 60 may be directly controlled from the control panel 170using the four-way valve 173, it is desirable, particularly whenfrequent changes of the length setting are required, to provide meansfor automatic positioning of the carriage. A convenient way ofaccomplishing this is to provide a servo system employing multi-tumpotentiometers connected in a bridge circuit, the first being manuallysettable in accordance with the length of the desired workpiece and thesecond being coupled to the motor for follow-up to reestablish acondition of circuit balance. Thus referring to FIG. 19, a controlcircuit is provided having a first multi-turn potentiometer 180 havingterminals 181, 182 and a wiper 183. The latter is connected to amanually set scale 184 calibrated directly in units of length andsettable at the control station.

Connected across the potentiometer 180 is a second, or follow-up,potentiometer 190 having terminals 191, 192 and a wiper 192, but in thiscase the wiper has a mechanical connection 194 to the motor 60.

Innerconnecting the wipers is a sensitive polarized relay 200 havingalternatively energized contacts 201,

202 with relays 203, 204 imposed in the circuit for energization offorward and reverse terminals 205, 206 of a four-way valve 210. Thelatter has lines 211, 212 connected to a source of pressure and a sumprespectively and connections 213, 214 which are connected to the supplyorifices 65, 66 of the motor.

The bridge circuit may be supplied from any suitable source of directvoltage as indicated at B and the relays 203, 204 and valve 210 may beoperated from a suitable source via lines L1, L2.

In operation, manual setting of the wiper 183 in accordance with thesetting scale 184 unbalances the bridge, thereby energizing thepolarized relay which makes contact at 201 or 202 depending upon thedirection of the unbalance. Assuming contact is made at 202, theforward" terminal 205 of the valve 210 is energized, causing the motor60 to rotate in a direction to drive the carriage forwardly, accompaniedby a follow-up movement of the wiper 193 of the second potentiometer.When the carriage has moved the follow-up potentiometer to a point whichcorresponds to the setting of the scale 184, the bridge achieves thebalanced condition, the carriage stops, and may then be clamped inplace.

It will be apparent that a more elaborate self-positioning scheme of theanalog type may be employed using selysns, or, if desired, a high degreeof positioning accuracy may be obtained using digital techniques. In thelatter event manual means may be employed for establishing a number ofdigits corresponding to a desired cut-off length and a digital feed backarrangement, coupled to the motor or carriage may be used for energizingthe motor until a condition of digital coincidence is achieved,following which the motor is automatically de-energized with thecarriage in the set position.

The above discussion has been directed toward a preferred automatic andfully powered embodiment of the invention, but it will be understoodthat certain of the inventive features may be used with only manualpowering. For example, the clamp structure disclosed in FIG. 6 may bemodified by extending the arm 84, connected to the cam 82, so that itterminates in a gripping handle to take the place of the actuator towhich the arm is normally coupled. Moreover, if desired, the drivingmotor 60 (see FIG. 4) may be omitted and the carriage may be propelledalong the rail simply by manual pushing. In such event, however, thecalibrated tape which extends along the rail 40 would be fixed and anindex would be provided on the carriage so that the setting of the stopis directly and constantly indicated to the operator right at thecarriage position. The rocking movement of the stop may also, ifdesired, be accomplished manually by providing a rigid, radiallyextending arm on the shaft 110, by providing biasing means, for example,in a form of a stiff spring in the space 123 of the sleeve to maintainthe stop surfaces in normal, bottomed condition, and by angling theinitial portion 131 of the cam track at a convenient steep angle and byshortening the cam track to provide free upward swing after only minorendwise movement.

As used herein, the term extending the width of the conveyor, referringto the stop surface, has to do with the fact that the stop surfaceextends along the width dimension of the conveyor, the length of thestop surface being such as to insure stricking by the workpiece.

I claim as my invention:

1. In a dead stop length gage for defining the cut-off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, acarriage riding on the rail, means for positioning the carriage and forclamping the carriage to the rail at a selected position, a stop memberon the carriage having a stop surface extending the width of theconveyor, a shaft extending parallel to the rail for mounting the stopmember, a sleeve mounted on the carriage and telescoped over the shaftso that the shaft is both axially and rotationally movable in thesleeve, the sleeve being recessed to form an annular fluid chamberhaving alternatively pressurized inlets at its ends and the shaft havingan integral piston movable in the chamber for moving the shaft between areference position in which the stop surface on the arm is positioned toengage the oncoming stock and a retracted position, the sleeve having aninternal cam track and the shaft having a cam follower, with the camtrack being so arranged that upon retracting movement of the shaft thestock member is both retracted from the engaged end of the severedworkpiece and swung upwardly out of the way of the workpiece forcontinued movement of the workpiece along the conveyor.

2. The combination as claimed in claim 1 in which the remote one of thepressurized inlets has a fluid accumulator and in which the cam trackhas an initial axially extending portion to permit retreating movementof the stop member straight back from reference position, withsubsequent restoration to the reference position, upon impact of thestop surface by an oncoming length of stock.

3. In a dead stop length gage for defining the cut-off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, acarriage riding on the rail, means for driving the carriage along therail and for clamping the carriage to the rail at a selected position, astop member in the form of an arm having a stock-engaging surfaceextending the width of the conveyor, means including a telescoped shaftand sleeve having an axis parallel to the rail for supporting the stopmember for swinging movement as well as for limited axial retractingmovement, an axial position reference stop interposed between the stopmember and carriage for defining the working position of the stopmember, fluid actuator means interposed between the stop member andcarriage for pressing the stop member into bottoming engagement with thereference stop during the gaging of the work piece and for retractingthe stop member axially away from the severed workpiece, and a cam andcam follower interposed between the shaft and the sleeve and so formedthat upon retraction the stop member is retracted from the severedworkpiece and swung upwardly out of the way of the workpiece forcontinued movement of the latter.

4. In a dead stop length gage for defining the cut-off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, acarriage riding on the rail, power means for moving the carriage alongthe rail, means for clamping the carriage to the rail at a selectedposition, a stop member on the carriage in the form of an arm presentinga stop surface across the width of the conveyor, a hinge connectionbetween the stop member and the carriage extending along an axisparallel to the rail and permitting limited retracting movement of thestop member along the axis as well as upward swinging movement, an axialposition reference stop between the carriage and stop member, a cam andcam follower interposed between the carriage and stop member, areversible fluid actuator interposed between the carriage and stopmember having means for applying fluid pressure in one direction fornormally maintaining the stop member seated against the reference stopfor positioning the workpiece, said cam having a straight axial portionand an angled portion so that when the direction of pressure in thefluid actuator is reversed the stop member retracts away from theengaged end of the severed workpiece followed by upward swingingmovement of the stop member out of the way of the workpiece forcontinued movement of the workpiece along the conveyor.

5. In a dead stop length gage for defining the cut-off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor andhaving a rack thereon, a carriage riding on the rail, the carriagehaving a self contained motor and drive pinion for engaging the rack,means for positively clamping the carriage to the rail at a selectedposition, a stop member on the carriage arranged to extend across thewidth of the conveyor and hinged to the carriage about an axis parallelto the rail to permit upward swinging movement as well as limitedretracting movement in the direction of the axis, and axial positionreference stop interposed between the carriage and stop member, a camand cam follower interposed between the carriage and the stop member,fluid actuator means interposed between the carriage and stop member fornormally maintaining the stop member bottomed on the positioning stopand having provision for reversal of pressure, the cam and cam followerupon reversal of pressure being so formed as to cause the stop member toretract from the engaged end of the severed workpiece and to swingupwardly out of the way of the workpiece for continued movement of thework along the conveyor. v

6. In a dead stop length gage for defining the cut off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, acarriage riding on the rail, means for moving the carriage along therail and for positively clamping it to the rail at a selected position,a stop member in the form of an arm having a stop surface extendingacross the width of the conveyor and having a mounting shaft extendingaxially parallel to the rail, a sleeve mounted on the carriage andtelescoped over the shaft so that the shaft may both rotate and move inan axial direction with respect to the sleeve, the sleeve having at eachof its ends a fluid seal with respect to the shaft and defining anannular chamber, a piston integral with the shaft for endwise movementin the chamber, an annular insert filling the chamber at one end of thesleeve so that the piston is limited to movement between a referenceposition and a retracted position, the insert having a cam track formedtherein and the shaft having a cam follower riding in the track, the camtrack being so formed that when the piston is pressurized for retractingmovement the cam follower retracts the stop member and swings itupwardly away from the engaged end of the severed workpiece forcontinued travel of the workpiece along the conveyor.

7. In a dead stop length gage for defining the cut-off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, therail being arranged vertically edgewise to present parallel upper andlower edges, a carriage having a frame consisting of a pair of vertical,spaced apart end members arranged in parallel relation including acentral portion of C-shaped cross section extending between them andhaving upper and lower arms defining a central space which extends allthe way through theframe, the rail being accommodated in such space withits upper and lower edges adjacent the upper and lower arms,anti-friction means associated with the upper arm for slidingly mountingthe carriage with clearance between the rail and the lower arm, clampingmeans in the carriage (associated with) including a cam mounted upon theupper arm for applying clamping pressure to the upper edge of the railthereby bodily lifting the carriage to produce clamping engagementbetween the lower arm and the lower edge of the rail, a stop memberhinged to the carriage having a stop surface extending across the widthof the conveyor in obstructing relation to an oncoming length of stock,and means including an hydraulic actuator for retracting the stop fromthe end of a severed workpiece and for swinging it clear of theworkpiece for transport of the workpiece by the conveyor to a positionof discharge.

8. In a dead stop length gage for defining the cut-off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, therail being arranged vertically edgewise to present parallel upper andlower edges, a carriage having a frame of C shape including upper andlower arms embracing the rail, anti-friction means on the carriage framefor engaging the upper edge and the sides of the rail while providing alimited amount of clearance between the lower edge of the rail and thelower arm of the frame, a shoe captive in the upper arm and extendingthrough an opening therein from a point opposite the upper edge of therail to a point above the upper arm, a cam mounted in the carriage frameabove the upper arm thereof and having means for rocking the cam tocause downward crowding against the presented upper surface of the shoefor relative lifting of the frame to take up the clearance and forclamping of the lower arm against the lower edge of the rail, a stopmember on the carriage having a stop surface extending across the widthof the conveyor in obstructing relation to an oncoming length of stock,the stop member being hinged about an axis parallel to the rail andhaving means for imparting rocking movement for rocking the stop memberout of obstructing position for passage of the workpiece along theconveyor.

1. In a dead stop length gage for defining the cut-off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, acarriage riding on the rail, means for positioning the carriage and forclamping the carriage to the rail at a selected position, a stop memberon the carriage having a stop surface extending the width of theconveyor, a shaft extending parallel to the rail for mounting the stopmember, a sleeve mounted on the carriage and telescoped over the shaftso that the shaft is both axially and rotationally movable in thesleeve, the sleeve being recessed to form an annular fluid chamberhaving alternatively pressurized inlets at its ends and the shaft havingan integral piston movable in the chamber for moving the shaft between areference position in which the stop surface on the arm is positioned toengage the oncoming stock and a retracted position, the sleeve having aninternal cam track and the shaft having a cam follower, with the camtrack being so arranged that upon retracting movement of the shaft thestock member is both retracted from the engaged end of the severedworkpiece and swung upwardly out of the way of the workpiece forcontinued movement of the workpiece along the conveyor.
 2. Thecombination as claimed in claim 1 in which the remote one of thepressurized inlets has a fluid accumulator and in which the cam trackhas an initial axially extending portion to permit retreating movementof the stop member straight back from reference position, withsubsequent restoration to the reference position, upon impact of thestop surface by an oncoming length of stock.
 3. In a dead stop lengthgage for defining the cut-off length of a workpiece from a length ofstock in a band saw or the like, the combination comprising a conveyorextending downstream from the band saw, a rail mounted longitudinallyalong one side of the conveyor, a carriage riding on the rail, means fordriving the carriage along the rail and for clamping the carriage to therail at a selected position, a stop member in the form of an arm havinga stock-engaging surface extending the width of the conveyor, meansincluding a telescoped shaft and sleeve having an axis parallel to therail for supporting the stop member for swinging movement as well as forlimited axial retracting movement, an axial position reference stopinterposed between the stop member and carriage for defining the workingposition of the stop member, fluid actuator means interposed between thestop member and carriage for pressing the stop member into bottomingengagement with the reference stop during the gaging of the work pieceand for retracting the stop member axiaLly away from the severedworkpiece, and a cam and cam follower interposed between the shaft andthe sleeve and so formed that upon retraction the stop member isretracted from the severed workpiece and swung upwardly out of the wayof the workpiece for continued movement of the latter.
 4. In a dead stoplength gage for defining the cut-off length of a workpiece from a lengthof stock in a band saw or the like, the combination comprising aconveyor extending downstream from the band saw, a rail mountedlongitudinally along one side of the conveyor, a carriage riding on therail, power means for moving the carriage along the rail, means forclamping the carriage to the rail at a selected position, a stop memberon the carriage in the form of an arm presenting a stop surface acrossthe width of the conveyor, a hinge connection between the stop memberand the carriage extending along an axis parallel to the rail andpermitting limited retracting movement of the stop member along the axisas well as upward swinging movement, an axial position reference stopbetween the carriage and stop member, a cam and cam follower interposedbetween the carriage and stop member, a reversible fluid actuatorinterposed between the carriage and stop member having means forapplying fluid pressure in one direction for normally maintaining thestop member seated against the reference stop for positioning theworkpiece, said cam having a straight axial portion and an angledportion so that when the direction of pressure in the fluid actuator isreversed the stop member retracts away from the engaged end of thesevered workpiece followed by upward swinging movement of the stopmember out of the way of the workpiece for continued movement of theworkpiece along the conveyor.
 5. In a dead stop length gage for definingthe cut-off length of a workpiece from a length of stock in a band sawor the like, the combination comprising a conveyor extending downstreamfrom the band saw, a rail mounted longitudinally along one side of theconveyor and having a rack thereon, a carriage riding on the rail, thecarriage having a self contained motor and drive pinion for engaging therack, means for positively clamping the carriage to the rail at aselected position, a stop member on the carriage arranged to extendacross the width of the conveyor and hinged to the carriage about anaxis parallel to the rail to permit upward swinging movement as well aslimited retracting movement in the direction of the axis, and axialposition reference stop interposed between the carriage and stop member,a cam and cam follower interposed between the carriage and the stopmember, fluid actuator means interposed between the carriage and stopmember for normally maintaining the stop member bottomed on thepositioning stop and having provision for reversal of pressure, the camand cam follower upon reversal of pressure being so formed as to causethe stop member to retract from the engaged end of the severed workpieceand to swing upwardly out of the way of the workpiece for continuedmovement of the work along the conveyor.
 6. In a dead stop length gagefor defining the cut off length of a workpiece from a length of stock ina band saw or the like, the combination comprising a conveyor extendingdownstream from the band saw, a rail mounted longitudinally along oneside of the conveyor, a carriage riding on the rail, means for movingthe carriage along the rail and for positively clamping it to the railat a selected position, a stop member in the form of an arm having astop surface extending across the width of the conveyor and having amounting shaft extending axially parallel to the rail, a sleeve mountedon the carriage and telescoped over the shaft so that the shaft may bothrotate and move in an axial direction with respect to the sleeve, thesleeve having at each of its ends a fluid seal with respect to the shaftand defining an annular chamber, a piston integral with the shaft forendwise movement in the chamber, aN annular insert filling the chamberat one end of the sleeve so that the piston is limited to movementbetween a reference position and a retracted position, the insert havinga cam track formed therein and the shaft having a cam follower riding inthe track, the cam track being so formed that when the piston ispressurized for retracting movement the cam follower retracts the stopmember and swings it upwardly away from the engaged end of the severedworkpiece for continued travel of the workpiece along the conveyor. 7.In a dead stop length gage for defining the cut-off length of aworkpiece from a length of stock in a band saw or the like, thecombination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, therail being arranged vertically edgewise to present parallel upper andlower edges, a carriage having a frame consisting of a pair of vertical,spaced apart end members arranged in parallel relation including acentral portion of C-shaped cross section extending between them andhaving upper and lower arms defining a central space which extends allthe way through the frame, the rail being accommodated in such spacewith its upper and lower edges adjacent the upper and lower arms,anti-friction means associated with the upper arm for slidingly mountingthe carriage with clearance between the rail and the lower arm, clampingmeans in the carriage (associated with) including a cam mounted upon theupper arm for applying clamping pressure to the upper edge of the railthereby bodily lifting the carriage to produce clamping engagementbetween the lower arm and the lower edge of the rail, a stop memberhinged to the carriage having a stop surface extending across the widthof the conveyor in obstructing relation to an oncoming length of stock,and means including an hydraulic actuator for retracting the stop fromthe end of a severed workpiece and for swinging it clear of theworkpiece for transport of the workpiece by the conveyor to a positionof discharge.
 8. In a dead stop length gage for defining the cut-offlength of a workpiece from a length of stock in a band saw or the like,the combination comprising a conveyor extending downstream from the bandsaw, a rail mounted longitudinally along one side of the conveyor, therail being arranged vertically edgewise to present parallel upper andlower edges, a carriage having a frame of C shape including upper andlower arms embracing the rail, anti-friction means on the carriage framefor engaging the upper edge and the sides of the rail while providing alimited amount of clearance between the lower edge of the rail and thelower arm of the frame, a shoe captive in the upper arm and extendingthrough an opening therein from a point opposite the upper edge of therail to a point above the upper arm, a cam mounted in the carriage frameabove the upper arm thereof and having means for rocking the cam tocause downward crowding against the presented upper surface of the shoefor relative lifting of the frame to take up the clearance and forclamping of the lower arm against the lower edge of the rail, a stopmember on the carriage having a stop surface extending across the widthof the conveyor in obstructing relation to an oncoming length of stock,the stop member being hinged about an axis parallel to the rail andhaving means for imparting rocking movement for rocking the stop memberout of obstructing position for passage of the workpiece along theconveyor.